The goal of this project is to obtain better insight into the complexity of pain disorders, specifically concerning the assessment of different pain types as well as pain-related disablement and its association with mental health and quality of life. This will be achieved by developing an ontology which will then be used to integrate five existing datasets that broadly encompass the major types of pain (orofacial pains, temporomandibular disorder pain, headache) recognized to occur in the oral and associated regions and incorporating a broad array of measures consistent with a biopsychosocial perspective regarding pain. Patients complaining of a single regional persistent pain typically manifest symptoms suggestive of more than one pain disorder. Presently, and although still uncertain, the pain field regards different types of pain as emerging from different mechanisms. Consequently, patients suffering from a given type of persistent pain receive treatments based on how that pain has been classified, perhaps inappropriately. The datasets cover the same domain, but are distinct in various respects: (1) some variables are identical across datasets, others involving, for instance, somatization, depression and anxiety, are different because measured with distinct instruments; (2) the data exhibit different levels of granularity; (3) because of their distinct origins (US, UK, Sweden, Israel, and Germany), the datasets incorporate cultural influences related to pain report that have an impact on the comparability of the data sets, despite the use of common instruments. The ontology will make it possible to describe the datasets in a uniform and formal way, and be general enough to include other datasets in the same domain once they become available. The importance of this endeavor lays in its contribution to solving an important problem, namely that the phenotype of many pain conditions is insufficiently defined in terms of the scope, the natural history and/or clinical course of the disease subgroup of interest, and, most importantly, with respect to disease traits for which laboratory research has provided important pathogenetic insight. The main clinical question that we will be able to answer by merging these datasets is how patho-anatomy and pathophysiology - in this case in the context of TMD and orofacial pains - have an impact on pain-related disablement and quality of life. Because the ontology will provide a formal representation of widely used assessment instruments in the domain of mental health, its applicability will exceed by far the more narrow domain that is covered in the proposed project for practical reasons. The ontology will be built following the widely accepted and in Nature published principles adhered to in the Open Biomedical Ontology Foundry (OBO-Foundry, using Basic Formal Ontology (BFO), and Referent Tracking (RT) as generic semantic technologies. By working in collaboration with The International RDC/TMD Consortium Network, and the Orofacial Pain Special Interest Group of the International Association for the Study of Pain, this ontology is likely to become a standard in the domain. PUBLIC HEALTH RELEVANCE: There is general consensus that combined biomedical and biopsychosocial methods best support the assessment and management of pain and dysfunction caused by musculoskeletal disorders and the impact thereof on mental health and quality of life. The ontology to be developed in the proposed effort embodies the conceptual theories underlying relevant biomedical models (anatomy and pathophysiology related to temporomandibular joints), psychological models and biopsychosocial models. It thus supports an integrated and multidimensional approach concerning physical and psychosocial factors involved in pain and dysfunction, and will help in the conceptualization and management of pain-related disorders for various health care professionals.